Ive just bought a Uk 99 Turbo and Ive no idea if anyone has been fiddling with it. My question is, when being driven fairly easily Ive noticed a hesitancy in the turbo at about 2500 revs. This is especially noticeable if youre cruising on the Motorway. Someone suggested to me it could be the airflow meter or the Maf sensor. Any ideas?

PS no engine management lights or anything

 

when it is on idle are the revs going up and down ? that is one sign of the maf mine had the same problem as yours i would say if it is not your maf it will be the boost solinoid . i have the problem of the dredded maf sensor at least every 2 months on mine .

 

maf sensor is always a good place 2 start, 75pound from suabaru plus vat, if you are not sure if it has bein changed id get it done asap and stay off boost till then

 

99my feels like its missfireing when going steady they all do that mate no honestley there was a buliten out from subaru it effected some cars more than others but get it checked out there is a upgrade for the ecu can only be done by subaru service managers

 

MAF

 

Hmm my 99 wagon has similar problem - but tends to be more noticeable when cold - slight hesitation around 2500rpm - also when idle sometimes over revs slightly - looks like a MAF for me too then?

 

Car is idling fine its just this one thing. Maybe its just the age of it. Prob take it down to a dealer and see if he can put it on dyno. Although theyre full of it as I rang them yesterday to ask would 05 sti wheels fit on as id heard there was a different stud pattern and their service guy said yeah no problem. Im now selling a set of wheels that dont fit on my car!

Thanks for the advice anyway

 

I have a 00my and mine does exactly the same, It is NOT the MAF, I know this because i have recently had the maf changed at the clinic for another problem. I have not heard of the ECU upgrade but will phone subaru in a minute and find out.

 

By the way, 05 STi wheels have a PCD of 112mm compared to 100mm on the classic and newage upto and inc 04

 

The my99 ecu is supposed to be better than the my00. I had this problem, but only when cold. The ecu is constantly trying to adjust the fuel/ignition timing when the engine is cold, to keep emissions down. Some people have reported that a new lambda sensor can help the problem, but I don't think anyone has actually sorted the issue.

Is when the car is cold?

 

As per what Chris says, Swapping the lambda can make a slight difference, but never cures it once & for all, It kind of feels like you have a Caravan being towed behind you, Sapping the power every now & then as it bobs up & down

Dean

 

Cheers Chris - as mine does it mainly when cold.

 

i have got a fmic so have to have a induction kit what i hear are no good for maf sensors but i have had 5 new mafs in a year what can i do?

 

What induction kit have you got? Only K&N and Apexi seem to work on impreza's. You must make sure that the induction kit is secured to the body work in some way or another. It's not the increased airflow that damages the maf, it's the extra vibration.

 

it is fixed to the body .i have tried a k an n filter but that didnt work so i put a foam pipercross on and that seemed to last longer but now it has gone .